A technique to project an image onto a screen of arbitrary shape without distortion has been already put into practice in virtual reality creating apparatuses. Examples of such a prior art include a following literature and the like. In these virtual reality creating apparatuses, an input image signal was a computer graphics signal or a DV signal generated for the virtual reality creating apparatus. Moreover, relational expressions for distortion correction used to project an image without distortion (description about a relation between images before and after the distortion correction and a distortion correction table) were created within the system.
Japanese Patent No. 3387487